Multi-mode mobile device based radio access network selection method for idle mode operations

ABSTRACT

A method at a mobile device, and the mobile device, the method selecting a subset of radio access technologies available to the mobile device over which a predetermined set of services on the mobile device is available; and deactivating monitoring, or reducing a monitoring frequency, of at least one radio access technology not within the selected subset of radio access technologies.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to multi-mode mobile devices,and more particularly, to radio access network selection on a multi-modemobile device.

BACKGROUND

Multi-mode mobile devices can support and connect to multiple radioaccess technologies simultaneously. Examples of radio accesstechnologies include, but are not limited to Global System for MobileCommunication (GSM), Code Division Multiple Access (CDMA), UniversalMobile Telecommunication System (UMTS)/Wideband Code Division MultipleAccess (WCDMA), CDMA2000 1x and 1xEV-DO, Long Term Evolution (LTE), LongTerm Evolution—Advanced (LTE-A), among others. In addition to theseradio access technologies which operate on licensed spectrum and aretypically known as cellular radio access technologies, a multi-modemobile device may support variants of IEEE 802.x-based radio accesstechnologies such as WiFi, WiMAX, and provide Wireless Local AreaNetwork (WLAN) service on unlicensed spectrum. A multi-mode mobiledevice may also communicate through short range wired or wirelesscommunications such as IrDA, Bluetooth™, near field communications(NFC), Universal Serial Bus (USB), amongst others. Moreover, amulti-mode mobile device capable of supporting Unlicensed Mobile Access(UMA) can roam and handover between cellular and WLAN radio accesstechnologies.

When a multi-mode mobile device is in a coverage area of multiple radioaccess networks, the mobile device may register with more than one,provided that the corresponding radio access technology at the device isturned on and active. Current radio technology standards require themulti-mode mobile device to monitor all of the radio access networks towhich it is registered.

As used herein, a multi-mode mobile device that is not performing anactive data transfer is said to be operating in IDLE mode. In IDLE mode,the device performs discontinuous reception (DRX) where it periodicallyturns on its receiver to listen for possible “paging”, “beacon”, orsimilar messages indicating the presence of incoming voice or datacalls. When not listening for incoming calls, the device deactivates itsreceiver to conserve battery life. The use of the term IDLE in thepresent disclosure includes states in certain radio access technologiesthat are considered connected, such as within UMTS when the device is ina Cell_PCH or URA_PCH state.

With the evolution in wireless technology, services such as voice, shortmessage service (SMS), emergency call, and/or other applications may allbe supported by different radio access technologies. It is possible thata multi-mode mobile device may be able to obtain all the subscribedservices from one or more radio access technologies to which the mobiledevice is capable of connecting. However, a multi-mode mobile device isstill required to wake up periodically to listen to paging/beaconmessages from all the radio access networks to which it is registered.This monitoring of multiple networks decreases the already limitedbattery life of a multi-mode mobile device.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be better understood with reference to thedrawings, in which:

FIG. 1 is an exemplary communication environment in which a multi-modemobile device and method in accordance with one embodiment may bepracticed;

FIG. 2 is a process diagram illustrating a radio access networkselection method for idle mode operations in accordance with oneembodiment;

FIG. 3 is a process diagram illustrating a radio access networkselection method for idle mode operation in accordance with analternative embodiment;

FIG. 4 is a process diagram illustrating a radio access networkselection method for idle mode operation in accordance with yet anotherembodiment; and

FIG. 5 is a block diagram showing an exemplary multi-mode mobile device.

DETAILED DESCRIPTION

The present disclosure provides a method at a mobile device comprising:selecting a subset of radio access technologies available to the mobiledevice over which a predetermined set of services on the mobile deviceis available; and deactivating monitoring, or reducing a monitoringfrequency, of at least one radio access technology not within theselected subset of radio access technologies.

The present disclosure further provides a mobile device, comprising, aprocessor; and a communications subsystem, wherein the processor andcommunications subsystem cooperate to: select a subset of radio accesstechnologies available to the mobile device over which a predeterminedset of services on the mobile device is available; and deactivatemonitoring, or reduce a monitoring frequency, of at least one radioaccess technology not within the selected subset of radio accesstechnologies.

Advantageously, by selecting a radio access network that offers all therequired services subscribed for a multi-mode mobile device for idlemode operations, or by selecting radio access networks each offering asubset of the required services and together providing all the servicesrequired, redundant monitoring of paging/beacon messages from all othersupported radio access technologies can be avoided. In one embodiment,this may be achieved by turning on access mode(s) of the mobile deviceto the radio access technology or radio access technologies selected forIDLE mode operations and turning off access modes to all other supportedradio access technologies.

In another embodiment, by reducing the discontinuous reception (DRX)cycle of all other supported radio access technologies that have notbeen selected for IDLE mode operations, the frequency of redundantindependent monitoring can be reduced. This reduces current consumptionof the multi-mode mobile device during idle mode operations.

The term “mobile device”, as used herein, could be any wireless device,including, but not limited to a mobile station, user equipment (UE),personal digital assistant, data enabled cellular telephone, pager,laptop, among others.

The term access point (AP), as used herein, indicates a wireless servicepoint and may include a node B, evolved node B (eNB), home evolved nodeB (HeNB), a base station or relay in WiMAX, an access point in 802.11 orany such similar wireless service point. The present disclosure is notlimited to any particular type of access point.

Reference is now made to FIG. 1, which shows an exemplary system modelin which a mobile device 110 communicates with a plurality of accesspoints. In the example of FIG. 1, mobile device 110 is capable ofcommunicating with access points 120, 122 and 124. For example, in theembodiment of FIG. 1, access point 120 may be a UMTS access point,access point 122 may be a WiFi access point, and access point 124 may bean LTE access point. However, this is not limiting and other exampleswould be evident to those in the art having regard to the presentdisclosure. Further, if mobile device 110 is a multi-mode device itcould communicate with a plurality of access points 120, 122, and 124 atthe same time, provided they are of RAT types supported by themulti-mode device.

Access points 130 provide communication in separate areas for which themobile device is currently not capable of communicating due to coveragearea.

Access point 120, may interact with an access network 140, access point122 may interact with access network 142 and access point 124 mayinteract with access network 144 in the embodiment of FIG. 1. Eachaccess network 140, 142 and 144 may further interact with Internet 150.

As a mobile device 110 moves between cells, access points 120, 122, 124and 130 may provide better or worse signal quality for mobile device110, and thus the access point serving mobile device 110 may change.Further, signal quality may change based on other mobile devices withina cell, interference from other sources, among other factors. Further, adecision to monitor a specific access point may be based on data rates,cost for data, among other factors.

As indicated in the system model of FIG. 1, a plurality of accessnetworks 140, 142, and 144 may exist and the mobile device 110 may needto register with each of the plurality of access networks 140, 142, and144 in order to receive voice and data calls. The access points 120,122, 124 and 130 will each interact with an access network.

Further, the model of FIG. 1 does not show the content providers, suchas web servers, enterprise servers or others, that may provide datathrough an access network 140.

In accordance with the embodiment of FIG. 1, mobile device 110 is saidto be in IDLE mode when it has no active data connection. In IDLE mode,mobile device 110 must wake up periodically to monitor data activities.For example, if mobile device 110 is concurrently connected to a WCDMAnetwork with access point 120 and a WiFi (WLAN) network with accesspoint 122, it will need to monitor both networks independently. Morespecifically, mobile device 110 needs to wake its WCDMA receiver up tomonitor the paging indicator channel (PICH) of WCDMA and to wake itsWLAN receiver up to monitor beacon messages of WLAN every DRX period. Inone configuration, the DRX period is typically 1.28 seconds for WCDMAand 100 ms for WLAN.

TABLE 1 Comparison of Current Consumption of a Multi- mode Mobile DeviceOperating in IDLE Mode Current consumption Radio Access IDLE modecurrent increase with respect to Technology consumption (mA) WiFi only(%) 2G + WiFi 7.367 10.235 3G + WiFi 9.266 38.650 WiFi 6.683 0

Reference is now made to Table 1, which shows a comparison of currentconsumption of a multi-mode mobile device operating in IDLE mode. Morespecifically, Table 1 shows the increase in battery consumption when amulti-mode mobile device monitors cellular networks in addition tomonitoring a WLAN network during IDLE mode operations.

The first entry shows that current consumption is 7.367 mA when themobile device monitors a 2G radio access technology such as GSM/GPRS inaddition to monitoring a WiFi technology. This represents an increase ofapproximately 10% compared to a mobile device that monitors only WiFiduring IDLE mode operations. The second entry shows that currentconsumption is increased by approximately 40% if paging messages of a 3Gnetwork such as that for a WCDMA network are monitored in addition tomonitoring a WiFi network.

This independent monitoring by a multi-mode mobile device of allsupported and connected radio access networks in a coverage area ofmultiple radio access technologies drains the battery of the mobiledevice.

If a multi-mode mobile device stops listening to the paging channel of acellular network in a coverage area that also has WLAN coverage, thenthe mobile device battery life can be conserved.

Reference is now made to FIG. 2, which shows an embodiment of a methodfor selecting a radio access network for idle mode operations of amulti-mode mobile device requiring a set of services in a coverage areaof a plurality of radio access technologies (RATs) to which the mobiledevice is capable of connecting.

The multi-mode mobile device may be aware of the services offered byeach supported radio access network. This information may bepre-configured and stored on the device during manufacturing or it maybe configured by network carriers or the device user. In anotherembodiment, the mobile device may dynamically query a supported radioaccess network for this information. Those skilled in the art willappreciate that other options may be used to enable the mobile device todetermine what services each supported radio access network offers.

In one embodiment, a mobile device may be configured such that a certainradio access technology, if available, is prioritized over othersupported radio access technologies to provide certain types of service.For example, WLAN technology may be prioritized over GSM to provide dataservices to a multi-mode mobile device in an area that has both WLAN andGSM coverage.

In another embodiment, services subscribed for a multi-mode mobiledevice such as voice, SMS, emergency calls, electronic mail, audioand/or video streaming, social networking, RSS feeds, internet browsing,and/or other applications may be configurable by a device user. A userinterface may be provided on the mobile device for the device user tospecify the subset of subscribed services that are mandatory oressential.

Further, other factors such as time of day may be used to determinewhich services are required. For instance, the device user may specifyall subscribed services as mandatory during business hours whileselecting only certain data applications as mandatory andcircuit-switched voice calls as optional during the evening hours. Theseexamples are for illustrative purposes only and are not meant to belimiting.

Different user profiles may be set up on the mobile device to specifythe types of service the device user requires based on the time of dayor other configurable parameters. A mobile device may also have multipleuser accounts, each having one or more user profiles. Those skilled inthe art will appreciate that different ways of providing device user(s)with the flexibility of configuring the mobile device are possible.

The process of FIG. 2 starts at block 210 and proceeds to block 212 inwhich the multi-mode mobile device checks one of the plurality ofsupported and connected radio access technologies to determine whetherone offers the required set of services. The check may prioritize radioaccess technologies in one embodiment, such that a most desired RAT maybe checked first. Thus, in the embodiment of FIG. 2, all currentlyactivated RATs are checked in turn and one selected for IDLE mode whileothers are deselected. In an alternative embodiment, not shown, each RATis activated in turn until the required services are covered.

In one embodiment, the required set of services consists of all theservices subscribed for the mobile device. In another embodiment, theset of services are all the subscribed services that are configured asmandatory or essential for the mobile device. The set of servicesconfigured as mandatory may depend on other parameters such as the timeof day and the like as described previously. In yet another embodiment,the required set of services is the set of mandatory services configuredfor a chosen profile on the mobile device or the set of mandatoryservices configured for a chosen profile of an active user account onthe mobile device.

If the radio access technology is found to offer the required set ofservices at block 212, then the process proceeds to block 214 where theradio access technology found in block 212 that offers the set ofrequired services is selected for IDLE mode operations.

From block 214, the process then proceeds to block 216 where all othersupported radio access technologies that have not been selected for IDLEmode operations are deselected. Deselecting may comprise turning offaccess modes of the mobile device to these radio access technologies.This stops the mobile device from monitoring paging/beacon messages fromall other radio access technologies that have not been selected for IDLEmode operations. Alternatively, deselecting may comprise reducing a DRXcycle of these radio access technologies to decrease the frequency ofmonitoring the paging/beacon messages of all radio access technologiesthat have not been selected for IDLE mode operations. From block 216,the process then ends at block 220.

On the other hand, at block 212, if the radio access technology does notoffer the set of required services, the process proceeds to block 218 todetermine if there is any supported radio access technology that has notyet been checked. If yes, the process loops back to block 212 againwhere the next supported radio access technology that has not yet beenchecked is checked to determine if it offers the set of requiredservices. This process repeats itself until a supported radio accesstechnology is found to offer the set of required services, in whichcase, the process proceeds to block 214 as previously described. Inother words, block 212 stops checking all other supported radio accesstechnologies once a radio access technology is found to offer the set ofrequired services. However, at block 218, if it is determined that allthe supported radio access technologies have already been checked andnone of the supported radio access technologies offers the set ofrequired services, then the process continues to block 220 where theprocess ends. In this case, the device will continue to monitor all ofthe connected RATs.

In another embodiment, as shown in FIG. 3, a method is provided forselecting a radio access network for IDLE mode operations of amulti-mode mobile device requiring a set of services in a coverage areaof a plurality of radio access technologies.

In the method described in FIG. 3, if only a subset of the requiredservices is offered by a radio access technology, that radio accesstechnology is selected for IDLE mode operations. The process continuesto check the next supported radio access technology that offers theremainder or a subset of the remainder of the required services, untilall the required services are found to have been offered by one or moreradio access technologies that have been selected for IDLE modeoperations or until all the supported radio access technologies havebeen checked.

The process of FIG. 3 starts at block 310 and proceeds to block 312 inwhich the multi-mode mobile device checks one of the plurality of radioaccess technologies to determine whether it offers one or more requiredservices. The check at clock 312 may check whether the service requiredhas been covered by a previously selected RAT, in which case the RATbeing checked is only selected if it offers a service not offered by thepreviously selected RAT.

If the check at block 312 results in a determination that the RAT adds aservice not offered by a previously selected RAT, the radio accesstechnology is selected for IDLE mode operations at block 314. Selectingthe radio access technology for IDLE mode operations at block 314 maycomprise turning on an access mode of the mobile device to the selectedradio access technology if the access mode has not already been turnedon.

The process then proceeds to block 316 to determine if all the requiredservices are offered by one or more radio access technologies that havebeen selected for IDLE mode operations. If yes, the process proceeds toblock 318 where at least one supported radio access technology that hasnot been selected for IDLE mode operations is deselected. In some casesall of the supported radio access technologies not selected for idlemode can be deselected. In other cases, some of the supported radioaccess technologies not selected for IDLE mode may be kept on.Deselecting may comprise turning off access modes of the mobile deviceto these radio access technologies, or reducing the DRX cycle of theseradio access technologies that have not been selected for IDLE modeoperations. The process then ends at block 330.

At block 312, if the radio access technology does not offer one or morerequired services above those offered by previously selected radioaccess technologies, then the process proceeds to block 320.

Similarly, at block 316, if all the required services are not offered bythe selected radio access technologies, the process proceeds to block320.

At block 320, if there is any supported radio access technology that hasnot yet been checked, then the process loops back to block 312 where thenext supported radio access technology that has not yet been checked ischecked to determine if it offers one or more required services that arenot offered by any of the radio access technologies that have beenselected for IDLE mode operations. This process repeats itself until:(a) a supported radio access technology is found to offer all theremaining required services or a subset of the remaining requiredservices, in which case, the process proceeds to block 314 as previouslydescribed, or (b) all the supported radio access technologies have beenchecked. In the latter case, if all the supported radio accesstechnologies have been checked, the process then proceeds from block 320to block 330 and ends.

The embodiment of FIG. 3 is merely meant to be illustrative. Othermethods for finding the minimum number of RATS would be equallyapplicable. Further, in some embodiments, it may be sufficient to find acombination of RATs that offers a subset of currently active RATs, evenif such subset is not the minimally sized subset and thus not anexhaustive solution.

Considering a multi-mode mobile device supporting both WLAN and cellulartechnologies in an overlapping coverage area of both WLAN and cellularnetworks. If the mobile device only requires data services, the datatunnel of WLAN maybe prioritized over cellular technologies for cost andbandwidth or performance reasons. Such data tunnel managementimplementation is profitable to network operators because traffic can beoffloaded from the limited, licensed and cellular network bandwidth towider, free and unlicensed WLAN bandwidth. It is also valuable to themobile device user as the connection over WLAN is usually cheaper, ifnot free, and the bandwidth is much higher compared to that in acellular network.

Despite the common practice of prioritized tunnel implementation overWLAN, multi-mode mobile devices requiring only data services, accordingto the current practice, are still required to wake up periodically tolisten to paging/beacon messages from all the connected and registeredradio access networks. This independent monitoring of all networksdrains the battery of the mobile device. It consumes power and reducesbattery life of the mobile device.

In one embodiment, different priority schemes may be provided on themobile device for the different services. These priority schemes on themobile device may be configured by device users, network carriers and/oror service providers.

For example, considering a multi-mode mobile device supporting WLAN,UMTS and GSM technologies in an overlapping coverage area of both WLANand cellular networks which requires both data services andcircuit-switched voice services. The priority scheme may be set up suchthat data tunnel of WLAN is always prioritized over cellular networksfor data services even though cellular networks offer both data servicesand circuit-switched voice call services. The priority scheme mayfurther provide that UMTS is prioritized over GSM for circuit-switchedvoice call services. In that case, access modes of the mobile device toWLAN and UMTS may be turned on for IDLE mode operations, while accessmode to GSM may be turned off to reduce battery consumption.

Those skilled in the art will appreciate that various priority schemesmay be set up for cost, bandwidth, performance or other reasons.

Another embodiment of the present method is provided in FIG. 4 wheresupported radio access technologies will always be selected for IDLEmode operations based on a priority scheme for the required set ofservices. The prioritized radio access technologies are considered firstto determine whether all the required services are offered by one ormore of the selected prioritized radio access technologies. If not, theless prioritized radio access technologies will then be considered.

For example, if a subset of the required services is offered by aprioritized radio access technology, then that prioritized radio accesstechnology is selected for IDLE mode operations. The process thencontinues to check the next prioritized radio access technology thatoffers the remainder or a subset of the remaining required services,until all the prioritized radio access technologies that have beenselected for IDLE mode operations together offer all the requiredservices. If after checking all the prioritized radio accesstechnologies, and not all the required services are offered by theselected prioritized radio access technologies, the process proceeds tochecking the less prioritized radio access technology or technologies todetermine if any of them offers the remainder or a subset of theremaining required services, until all the supported radio accesstechnologies that have been selected for IDLE mode operations togetheroffer all the required services or until all the supported radio accesstechnologies have been checked.

Referring to FIG. 4, the process starts at block 410 and proceeds toblock 412, where radio access technologies are selected in accordance toa priority scheme. Selecting a radio access technology for IDLE modeoperations in block 412 may comprise turning on an access mode of themobile device to a selected prioritized radio access technology if theaccess mode has not already been turned on.

As described previously, the priority scheme may require certainprioritized radio access technology be selected all the time for certainservices even though the same services may have been offered by otherradio access technologies. Other priority scheme may require aprioritized radio access technology that offers all the requiredservices or the most number of required services be selected. Theseexamples are for illustrative purposes and are not limiting.

From block 412, the process proceeds to block 414 where a check is madeto determine whether the prioritized radio access technology ortechnologies that have been selected for IDLE mode operations offer allrequired services.

At block 414, if the selected prioritized radio access technologies arefound to offer all the required services, then the process proceeds toblock 416 where all other radio access technologies that have not beenselected for IDLE mode operations are deselected. Deselecting maycomprise turning off access modes of the mobile device to these radioaccess technologies which stops the mobile device from monitoringpaging/beacon messages from these radio access technologies.Alternatively, deselecting may comprise reducing DRX cycle of theseradio access technologies to decrease the frequency of monitoring thepaging/beacon messages of all the radio access technologies that havenot been selected for IDLE mode operations. Based on the above, thedevice goes into deep sleep with respect to the less prioritizednetworks or with respect to the supported radio access technologies thatare not selected for IDLE mode operations. From block 416, the processthen ends at block 420.

If, at block 414, it is found that not all required services are offeredby the one or more prioritized radio access technologies that have beenselected for IDLE mode operations, then the process proceeds to block312 of FIG. 3 where supported radio access technologies that have notyet been checked for the services that they offer are checked, and theprocess continues as described above with regards to FIG. 3.

Those skilled in the art will appreciate that in some embodiments, amulti-mode mobile device may have several user accounts. Each useraccount may have one or more user profiles, each having a different setof required services. Therefore, depending on which user account islogged on at the time and the profile that has been chosen by the deviceuser, the multi-mode mobile device may select a different radio accessnetwork for IDLE mode operations in the same coverage area. Access modesof a multi-mode mobile device to the different radio access technologiesare selectively turned on or off depending on the priority scheme (ifone exists), the service offerings of the different supported radioaccess networks, the set of services subscribed for or specified asmandatory for a chosen user profile, or for a user account of the mobiledevice which is logged on at the time.

An exemplary multi-mode mobile for use with the embodiments above isillustrated below with reference to FIG. 5. The multi-mode mobile deviceof FIG. 5 is however not meant to be limiting, but is provided forillustrative purposes. Other multi-mode mobile devices could also beused.

Multi-mode mobile device 500 is typically a two-way wirelesscommunication device having at least voice and data communicationcapabilities. Multi-mode mobile device 500 may have the capability tocommunicate with other computer systems on the Internet. Depending onthe exact functionality provided, the mobile device 500 may be referredto as a data messaging device, a two-way pager, a wireless e-maildevice, a cellular telephone with data messaging capabilities, awireless Internet appliance, a wireless device, a user equipment, or adata communication device, as examples.

Where mobile device 500 is enabled for two-way communication, it canincorporate a communication subsystem 511, including both a receiver 512and a transmitter 514, as well as associated components such as one ormore antenna elements 516 and 518, local oscillators (LOs) 513, and aprocessing module such as a digital signal processor (DSP) 520. In someembodiments, communication subsystem 511 may allow for communicationswith a plurality of RATs. In other embodiments, one or more furthercommunications subsystem 560 supporting other RATs could be provided onmobile device 500. As will be apparent to those skilled in the field ofcommunications, the particular design of the communication subsystem 511or 560 will be dependent upon the communication network in which thedevice is intended to operate. For example, mobile device 500 mayinclude a communication subsystem 511 designed to operate within theGPRS network or UMTS network. In some embodiments, a mobile device 500supporting WiFi could include a further communications subsystem 550.

Network access requirements will also vary depending upon the type ofnetwork 519. For example, In UMTS and GPRS networks, network access isassociated with a subscriber or user of mobile device 500. For example,a GPRS mobile device therefore requires a subscriber identity module(SIM) card in order to operate on a GPRS network. In UMTS a USIM or SIMmodule is required. In CDMA a removable user identity module (RUIM) cardor a SIM card is required. These will be referred to as a UIM interfaceherein. Without a valid UIM interface, a mobile device may not be fullyfunctional. Local or non-network communication functions, as well aslegally required functions (if any) such as emergency calling, may beavailable, but mobile device 500 will be unable to carry out any otherfunctions involving communications over the network 519. The UIMinterface 544 is normally similar to a card-slot into which a card canbe inserted and ejected like a diskette or PCMCIA card. The UIM card canhold many key configuration 551, and other information 553 such asidentification, and subscriber related information.

When required network registration or activation procedures have beencompleted, mobile device 500 may send and receive communication signalsover the network 519. Signals received by antenna 516 throughcommunication network 519 are input to receiver 512, which may performsuch common receiver functions as signal amplification, frequency downconversion, filtering, channel selection and the like, and in theexample system shown in FIG. 5, analog to digital (ND) conversion. NDconversion of a received signal allows more complex communicationfunctions such as demodulation and decoding to be performed in the DSP520. In a similar manner, signals to be transmitted are processed,including modulation and encoding for example, by DSP 520 and input totransmitter 514 for digital to analog conversion, frequency upconversion, filtering, amplification and transmission over thecommunication network 519 via antenna 518. DSP 520 not only processescommunication signals, but also provides for receiver and transmittercontrol. For example, the gains applied to communication signals inreceiver 512 and transmitter 514 may be adaptively controlled throughautomatic gain control algorithms implemented in DSP 520.

Network 519 may further communicate with multiple systems, including aserver and other elements (not shown). For example, network 519 maycommunicate with both an enterprise system and a web client system inorder to accommodate various clients with various service levels.

Mobile device 500 can include a microprocessor 538 which controls theoverall operation of the device. Communication functions, including dataand voice communications, are performed through communication subsystem511. Microprocessor 538 also interacts with further device subsystemssuch as the display 522, flash memory 524, random access memory (RAM)526, auxiliary input/output (I/O) subsystems 528, serial port 530,keyboard 532, speaker 534, microphone 536, a short-range communicationssubsystem 540 and any other device subsystems generally designated as542.

Some of the subsystems shown in FIG. 5 perform communication-relatedfunctions, whereas other subsystems may provide “resident” or on-devicefunctions. Notably, some subsystems, such as keyboard 532 and display522, for example, may be used for both communication-related functions,such as entering a text message for transmission over a communicationnetwork, and device-resident functions such as a calculator or tasklist.

Operating system software used by the microprocessor 538 may be storedin a persistent store such as flash memory 524, which may instead be aread-only memory (ROM) or similar storage element (not shown). Thoseskilled in the art will appreciate that the operating system, specificdevice applications, or parts thereof, may be temporarily loaded into avolatile memory such as RAM 526. Received communication signals may alsobe stored in RAM 526. Further, a unique identifier is also preferablystored in read-only memory.

As shown, flash memory 524 can be segregated into different areas forboth computer programs 558 and program data storage 555, 552, 554 and556. These different storage types indicate that each program canallocate a portion of flash memory 524 for their own data storagerequirements. Microprocessor 538, in addition to its operating systemfunctions, may enable execution of software applications on the mobiledevice. A predetermined set of applications that control basicoperations, including data and voice communication applications forexample, may be installed on mobile device 500 during manufacturing. Onesoftware application may be a personal information manager (PIM)application having the ability to organize and manage data itemsrelating to the user of the mobile device such as, but not limited to,e-mail, calendar events, voice mails, appointments, and task items.Other applications may include multimedia application, social networkingapplications, instant messaging application, among others.

In a data communication mode, a received signal such as a text messageor web page download may be processed by the communication subsystem 511and input to the microprocessor 538, which may further process thereceived signal for output to the display 522, or alternatively to anauxiliary I/O device 528. A user of mobile device 500 may also composedata items such as email messages for example, using the keyboard 532,which in one embodiment is a complete alphanumeric keyboard ortelephone-type keypad, in conjunction with the display 522 and possiblyan auxiliary I/O device 528. Such composed items may then be transmittedover a communication network through the communication subsystem 511.

For voice communications, overall operation of mobile device 500 issimilar; except that received signals would typically be output to aspeaker 534 and signals for transmission would be generated by amicrophone 536. Alternative voice or audio I/O subsystems, such as avoice message recording subsystem, may also be implemented on mobiledevice 500. Although voice or audio signal output is generallyaccomplished primarily through the speaker 534, display 522 may also beused to provide an indication of the identity of a calling party, theduration of a voice call, or other voice call related information forexample.

Serial port 530 in FIG. 5 would normally be implemented in a personaldigital assistant (PDA)-type mobile device for which synchronizationwith a user's desktop computer (not shown) may be desirable. Such a port530 would enable a user to set preferences through an external device orsoftware application and would extend the capabilities of mobile device500 by providing for information or software downloads to mobile device500 other than through a wireless communication network. The alternatedownload path may for example be used to load an encryption key onto thedevice through a direct and thus reliable and trusted connection tothereby enable secure device communication.

Alternatively, serial port 530 could be used for other communications,and could include as a universal serial bus (USB) port. An interface isassociated with serial port 530.

Other communications subsystems 540, such as a short-rangecommunications subsystem, is a further optional component which mayprovide for communication between mobile device 500 and differentsystems or devices, which need not necessarily be similar devices. Forexample, the subsystem 540 may include an infrared device and associatedcircuits and components or a Bluetooth™ communication module to providefor communication with similarly enabled systems and devices.

The embodiments described herein are examples of structures, systems ormethods having elements corresponding to elements of the techniques ofthis application. This written description may enable those skilled inthe art to make and use embodiments having alternative elements thatlikewise correspond to the elements of the techniques of thisapplication. The intended scope of the techniques of this applicationthus includes other structures, systems or methods that do not differfrom the techniques of this application as described herein, and furtherincludes other structures, systems or methods with insubstantialdifferences from the techniques of this application as described herein.

The invention claimed is:
 1. A method at a wireless device comprising:determining a set of required services for the wireless device, suchservices requiring a radio connection over at least one radio accesstechnology (RAT); selecting a first RAT from a plurality of radio accesstechnologies (RATs), the plurality of RATs being provided by a pluralityof radio access networks; determining that not every service from theset of required services is available over the first RAT; performing,until the set of required services is available over selected RATs, thesteps of: determining that a next RAT from the plurality of RATs offersservices that are not available over selected RATs; selecting the nextRAT; and determining whether the set of required services are availableover selected RATs; and when the set of required services is availableover the selected RATs, monitoring only the selected RATs when thewireless device is in idle mode, the monitoring comprising, forunselected RATS of the plurality of RATs: deactivating monitoring; orreducing a monitoring frequency.
 2. The method of claim 1, wherein therequired services are defined by a user, carrier, or manufacturer of thewireless device.
 3. The method of claim 1, wherein the required servicesvary based on time of day.
 4. The method of claim 1, wherein therequired services vary based on a selected profile.
 5. The method ofclaim 1, wherein the performing utilizes a prioritized list of possibleradio access technologies.
 6. The method of claim 1, wherein the radioaccess technologies use both licensed and unlicensed spectrum.
 7. Themethod of claim 6, wherein the radio access technology using licensedspectrum includes one or more of global system for mobilecommunications, code division multiple access, universal mobiletelecommunications standard, long term evolution, and long termevolution advanced.
 8. The method of claim 6, wherein the radio accesstechnology using unlicensed spectrum includes at least one of WiFi,WiMAX, or Bluetooth™.
 9. The method of claim 1, wherein determiningwhether the set of required services are available over the at least oneRAT is based on a dynamic query of the at least one RAT.
 10. A wirelessdevice, comprising: a processor; and a communications subsystem; whereinthe wireless device is configured to: determine a set of requiredservices for the wireless device, such services requiring a radioconnection over at least one radio access technology (RAT); select afirst RAT from a plurality of radio access technologies (RATs), theplurality of RATs being provided by a plurality of radio accessnetworks; determine that not every service from the set of requiredservices is available over the first RAT; perform, until the set ofrequired services is available over selected RATs, the steps of:determining that a next RAT from the plurality of RATs offers servicethat are not available from selected RATs; selecting the next RAT; anddetermining whether the set of required services are available overselected RATs; and when the set of required services is available overthe selected RATs, monitor only the selected RATs when the wirelessdevice is in idle mode, the monitoring comprising, for unselected RATsof the plurality of RATs: deactivating monitoring; or reducing amonitoring frequency.
 11. The wireless device of claim 10, wherein therequired services are defined by a user, carrier, or manufacturer of thewireless device.
 12. The wireless device of claim 10, wherein therequired services vary based on time of day.
 13. The wireless device ofclaim 10, wherein the required services vary based on a selectedprofile.
 14. The wireless device of claim 10, wherein the wirelessdevice is configured to perform the selecting the first RAT and theselecting the next RAT by using a prioritized list of possible radioaccess technologies.
 15. The wireless device of claim 10, wherein theradio access technologies use both licensed and unlicensed spectrum. 16.The wireless device of claim 15, wherein the radio access technologyusing licensed spectrum includes one or more of global system for mobilecommunications, code division multiple access, universal mobiletelecommunications standard, long term evolution, and long termevolution advanced.
 17. The wireless device of claim 15, wherein theradio access technology using unlicensed spectrum includes at least oneof WiFi, WiMAX, or Bluetooth™.
 18. The wireless device of claim 10,wherein the wireless device is configured to determine whether the setof required services are available over the at least one RAT based on adynamic query of the at least one RAT.